Hypersensitive teeth can cause pain and discomfort when subjected to changes in temperature, pressure or chemical action. Exposure of the dentin frequently leads to hypersensitivity. Dentin exposure may occur due to recession of the gums, periodontal disease or improper dental care. The exposed dentin surface contains channels or tubules that lead to the nerves within the pulp of the tooth. These tubules are filled with fluid. When exposed to external stimuli, the fluid within the tubules contracts or expands. This fluid movement triggers an instantaneous pain response, resulting in dentin hypersensitivity.
One approach to relieving dentin hypersensitivity is to block or occlude the dentin tubules through the use of occlusion agents, thereby preventing the external stimuli from reaching the dentin fluid. In order to determine the efficacy of occlusion agents, it is necessary to be able to quantify dentin tubules and assess the occlusion of dentin tubules.
Dentin tubules typically range from two to ten microns in diameter. Therefore, relatively high magnification microscopic techniques such as scanning electron microscopy (SEM), atomic force microscopy, or optical (for example, confocal) microscopy are typically used to visualize dentin tubules and the relative amount of dentin tubule occlusion. The images of the dentin surface that are obtained from an SEM or confocal microscope enable a qualitative assessment of the degree of tubule occlusion.
However, quantification of dentin tubule occlusion has been challenging. It is known to use visual scoring techniques to semi-quantify dentin tubules and tubule occlusion, but such techniques are highly subjective and inaccurate. Furthermore, quantification of dentin tubules through use of image analysis software has not been successful due to the non-homogeneity of dentin surfaces.
There is therefore the need to provide a method of accurately quantifying dentin tubules and assessing dentin tubule occlusion.